function stability_abbr = Classify(c1, c2)
% 稳定性分类函数

    epsilon = 1e-1;
    delta = c1^2 - 4*c2;

    if abs(c1) < epsilon && c2 > 0
        stability_abbr = 'HBP'; % Hopf分岔
        return;
    end

    if c1 > 0 && abs(c2) < epsilon
        stability_abbr = 'FBP'; % Fold分岔
        return;
    end

    if c2 < 0
        stability_abbr = 'USP'; % 不稳定鞍点
        return;
    end

    if c1 < 0 && c2 > 0 && delta >= 0
        lambda1 = (-c1 + sqrt(delta))/2;
        lambda2 = (-c1 - sqrt(delta))/2;
        if lambda1 > 0 && lambda2 > 0
            stability_abbr = 'UNP'; % 不稳定节点
            return;
        end
    end

    if c1 < 0 && c2 > 0 && delta < 0
        stability_abbr = 'UNF'; % 不稳定焦点
        return;
    end

    if c1 > 0 && c2 > 0 && delta >= 0
        lambda1 = (-c1 + sqrt(delta))/2;
        lambda2 = (-c1 - sqrt(delta))/2;
        if lambda1 < 0 && lambda2 < 0
            stability_abbr = 'SNP'; % 稳定节点
            return;
        end
    end

    if c1 > 0 && c2 > 0 && delta < 0
        stability_abbr = 'SNF'; % 稳定焦点
        return;
    end

    % 未分类的情况
    stability_abbr = 'Unknown';
end
